One issue in the design of any high-performance computing or networking gear is the issue of interconnection between printed circuit boards (PCBs), i.e., from one PCB to another PCB. Within a PCB, electronic processing circuitry can be interconnected using wiring layers within the printed circuit board. This type of interconnect can provide high performance and density—supporting up to thousands of interconnection wires, operating at rates potentially greater than 1-10 Gbps. However, interconnections between PCBs are more difficult, requiring either backplane-style boards that the interconnecting circuit boards plug into using backplane connectors, or cables. This results in the use of cable connectors (or backplane-style connectors) and bulk cable with wires or flex circuitry. As processing circuitry has steadily improved in performance and density, these board-to-board interconnection methods have become an increasingly-large bottleneck in design, since the density and bandwidth performance of cable connectors and electrical backplane connectors has not increased at the same rate as the processing circuitry.